As used herein, the term “cuff” is intended to mean an inflatable balloon attached around a tube, e.g. a tracheal tube. In tracheal tubes the purpose of the cuff is to function as a seal between the tube and the trachea in order to prevent air from getting out and bacteria entering the lungs. In other catheters, e.g. urine catheters, the purpose of the cuff is to block and secure the tube in the body part where it is inserted into.
Tracheal tubes are used for conveying air or gas mixtures delivered by an Intensive Care Unit or Anaesthesia ventilator, through a breathing circuit, into the patient airways. Tracheostomy cannulas can have the same use as tracheal tubes or can be installed on spontaneously breathing patients who for a particular disease or accidental reasons cannot breath autonomously and sufficiently without this airway bypass.
Conventionally, the cuff is obtained through a blowing process or via pre-extruded tubing expansion. The assembly process of the cuff on the tube consists of the following phases: cutting of the cuff ends, named collars; insertion of the cuff on the tube and correcting its positioning; and gluing with solvents or adhesive.
The result obtained from the above process is the formation of a kind of step similar to the collar cutting edge. This step represents a traumatic factor during intubation operation because of the possible abrasions it can cause. This problem is particularly relevant for children and infant patients where the diameter of the tubes is narrower and the collar thickness is crucial.
Another problem of the prior art process relates to the shaping and the assembly operations in manufacturing rendering the whole process slow, expensive and relying heavily on personnel experience and ability. It is important to notice that such problems become more relevant when the tube has a narrow diameter (e.g. for children and infant patients) and when the cuffs are made of polyurethane (PU) with reduced thickness and can be easily damaged during handling, tubing and gluing.
Another way to form a cuff on a tracheal tube is disclosed in for example, EP1733752, the entire contents of which is hereby incorporated by reference, which provides the production of silicon catheters having an antibonding agent in the zone of the cuff shaping which would entail inefficient time and high cost problems.
Accordingly, there is a need for forming a die for molding cuffs on plastic tubes whose technical characteristics are such that molding is simple and effective.